Many years ago, I came across this marvellous phenomenon, and it still delights me.
This unpunctuated sentence (though it isn’t really a sentence, as it makes no sense) contains the word ‘had’ eleven consecutive times:
George unlike Bill who had had had had had had had had had had had the teacher’s approval.
With correct punctuation, it becomes a perfectly valid sentence.
George, unlike Bill, who had had ‘had’, had had ‘had had’; ‘had had’ had had the teacher’s approval.
The scenario is an English lesson in which the students are learning to use the imperfect and the pluperfect tenses correctly. The imperfect tense is the simple past: ‘I played’, for example. The pluperfect tense refers to a time in the past, from which point an event further in the past is recounted: ‘I had played’.
So let’s invent a classroom exercise for George, Bill, and their classmates:
When Cinders got back from the ball, she went to find her little mousy friends. She told them that she had/had had* a wonderful evening.
*Delete as appropriate
Bill chooses ‘had’: She told them that she had a wonderful evening.
George gets it right, though, with ‘had had’: She told them that she had had a wonderful evening.
Lovely, isn’t it!
Notice that the sentence containing ‘had’ eleven times is in the pluperfect tense.